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 | Guest Editorial
Author : Agrawal, J.P.
Source : Defence Science Journal ; Vol:56(3) ; 2006 ; pp
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| | Hexanitrohexaazaisowurtzitane or CL-20 in India : Synthesis and characterisation
Author : Sikder, A.K. ;Gandhe, B.R. ;Agrawal, J.P. ;Sigh, Haridwar ;Sikdar , Nirmala
Source : Defence Science Journal ; Vol:52(2) ; 2002 ; pp 135-146
Subject : 623.4 Armaments and Ballistics;623 Military Science and Engineering
Keywords : ESCA ;Chemical analysis ;Diffractogram ;Explosives
Abstract : Hexanitrohexaazaisowurtzitane (HNIW) more commonly called CL-20, the highest density and the most powerful real world explosive, has been made with very high yield and a high product purity. CL-20 is thoroughly characterised by spectral data (IR, NMR and mass) along with electron spectroscopy for chemical analysis (ESCA) and X-ray diffractogram. Furthermore, small-scale sensitivity tests have also been carried out. |
| | Guest Editorial
Author : Agrawal, J.P.
Source : Defence Science Journal ; Vol:58(4) ; 2008 ; pp
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| | Thermal Decomposition Mechanism of Silver Nitrobenzoates
Author : Agrawal, A.P.;Yoganarasimhan, S.R.;Agrawal, J.P.
Source : Defence Science Journal ; Vol:36(3) ; 1986 ; pp 309-315
Subject : 547 Organic Chemistry
Keywords : Infra red spectra;Decarboxylation
Abstract : The infra-red spectra of silver salts of 3-mono-,3,5-di-and 2,4,6-tri-nitro-benzoic acids have been recorded at elevated temperature in a fabricated high temperature cell. The thermogravimetry i.e. TG analysis has also been carried out. The results of this study suggest that decomposition of these salts is a two stage process i.e. decarboxylation followed by explosion. |
| | Synthesis of 4,4'-Dimethyl-3,3',5,5'-Tetranitroazoxybenzene by Selective Reduction of Trinitrotolune
Author : Agrawal, J.P. ;Surve, R.N.;Lal, Mehi;Prasad, U.S.
Source : Defence Science Journal ; Vol:48(3) ; 1998 ; pp 323-328
Subject : 620.261 Explosives
Keywords : Explosives
Abstract : Selective reduction of trinitrotoluene in dioxane solution by H/sub 2/S/NH/sub 3/ yields a mixture containing 4-amino-2,6-dinitrotoluene, 4-hydroxylamino-2,6-dinitrotoluene and 4,4'-dimethyl- 3,3',5,5'-tetranitroazoxybenzene. Treatment of crude mixture with KI/HCl converts 4-hydroxylamino-2,6-dinitrotoluene into 4-amino-2,6-dinitrotoluene as well as increases the percentage of 4,4'-dimethyl-3,3,5,5'-tetranitroazoxybenzene. The resulting compound 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was isolated and characterised by IR, NMR and elemental analysis. Its thermal decomposition as well as explosive properties have been studied. The data indicate that TATB is stable up to 294 °c and is also insensitive to impact and friction. |
| | Nanomaterials in Pyrotechnics
Author : Sarawadekar, R.G.;Agrawal, J.P.
Source : Defence Science Journal ; Vol:58(4) ; 2008 ; pp 486-495
Subject : 620.1 Material Science and Technology
Keywords : Nanomaterials;Pyrotechnics;Nanocomposites;Nanometal powders;Nanooxidisers
Abstract : Pyrotechnics consist of metallic powders as fuels and different oxidisers which generally have particle size of > 5 m. The use of nano materials is expected to increase intimate contact between fuel oxidiser, and therefore, development of nano pyrotechnics based on nano fuels oxidizers along with their synthetic routes is considered of great interest. In this review, methods for the preparation of powders of nanometals: aluminium (Al), nickel (Ni), copper (Cu), titanium (Ti), iron (Fe), silver (Ag), and cobalt (Co) and; metallic oxides: molybdenum trioxide (MoO3), tungsten trioxide (WO3), iron (III) oxide (Fe2O3), copper (I) oxide (Cu2O), antimony trioxide (Sb2O3), nickel oxide (NiO), manganese dioxide (MnO2), and zirconium dioxide (ZrO2) along with their characterisation are discussed. Some nano oxidisers such as PbCO3, Mg(OH)2 , NH4ClO4, NH4NO3 have also been reported. Further, some nano pyrotechnic formulations Al-MO3, Al-WO3, Al- Fe2O3, Al-AP, Al-Bi2O3, Al-CaO based on nanofuels oxidisers have also been formulated. |
| | Chemistry of Metal Picramates Part II Copper and Silver
Author : Agrawal, J.P. ;Agrawal, S.P.
Source : Defence Science Journal ; Vol:20(4) ; 1970 ; pp 237-248
Subject : 547 Organic Chemistry
Keywords : Metal picramates ;Potentiometric methods
Abstract : Copper and silver picramates have been prepared and their compositions have been established by micro-analysis. This has been further confirmed by conductometric and potentiometric methods. I.R. studies of metal picramates show-H/sub 2/ N->M coordination where M is copper and silver. Various explosive properties of these picramates have also been studied. |
| | Tetrachloro Phthalic Anhydride Based Chloropolyesters for Inhibition of Double Base Rocket Propellants
Author : Agrawal, J.P.;Kulkarni, K.S.
Source : Defence Science Journal ; Vol:36(4) ; 1986 ; pp 409-420
Subject : 66 Chemical Technology;662.3 Propellants
Keywords : Inhibiting materials;Nitroglycerine absorption;Tetrachlorophthalic anhydride;NDPA
Abstract : The choice of inhibiting materials for double base and composite modified double base rocket propellants has always been a difficult problem because of the presence of nitroglycerine in these propellants and its subsequent migration from the propellants towards the inhibitor. The inhibition of double base rocket propellants with unsaturated polyesters has become popular in recent years, but they usually suffer from the drawback of high nitroglycerine absorption. This may be considerably lowered by exploiting the concept of introduction of electron acceptance sites in one of the components used for the synthesis of unsaturated polyesters. Chloropolyester-1 (CP-1) based on tetrachlorophthalic anhydride (TCP An), propylene glycol (PG) and maleic anhydride (MAn) and chloropolyester-2 (CP-2) based on TCPn, polyethylene glycol mol. wt. 200 (PEG-200) and MAn have been synthesised and characterised for ge ltime, exotherm peak temperature, rensile strength, % elongation, bond strength, water absorption, nitroglycerine absorption, heat resistance and flame retardance. The blends of CP-1 and CP-2 designated as CPB-2 (CP-1 :CP-2:: 20:80), CPB-4 CPB-6 and CPB-8 have also been formulated and charactrised for these properties. Based on the data for various characteristics, CPB-4 has been selected for inhibition and static evaluation of rocket propellants. The double base rocket propellant sustainers containing 2-NDPA have been inhibited with CPB-4 without the application on any barrier after conditioning. The pressure-time profiles were found to be smooth and flat in all cases, inferring that the CPB-4 inhibition system (without application of any barrier coat) is working satisfactorily. |
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